Zero-Degree Calorimeters at the LHC: Present and Future

The Zero-Degree Calorimeter (ZDC) is a far-forward hadronic calorimeter, primarily designed to measure spectator neutrons from ion-ion collisions. The ZDC are instrumental for the heavy-ion program at the LHC in their utilization for triggering and event selection. This talk will present the refurbished ATLAS ZDC for the now underway LHC Run 3, as well as the upgraded ZDC for both ATLAS and CMS in the HL-LHC (2029+)